Serialist's static pages (documentation, blog). We actually have ikiwiki generate its static content as HTML fragments using a modified page.tmpl template, and then the FastCGI powering our site grabs those fragments and embeds them in the standard dynamic site template.

Börn og tónlist - an Icelandic open-content site, primarily for kindergarten teachers, about music and music-related activites with children. Migrated from MediaWiki to IkiWiki in June 2013. Heavily changed appearance with only minimal changes to page.tmpl. Also its sister site Leikur að bókum, about children's books in a kindergarten/pre-school context.

Réseaulibre.ca - a mesh project in Montréal, most data is stored in the wiki, including IP address allocation and geographic data. Features map (osm) integration.

voice in time a voice recording studio located in Hamburg, Germany (rather complex build using ikiwiki only, providing CGI access for the customer)

nb instrument a workshop for beautifully handcrafted musical instruments, located in Hamburg, Germany (also one of our rather complex builds using ikiwiki only, providing CGI access for the customer)

coido architects architectural company, located in Hamburg, Germany and Rotterdam, Netherlands (also rather complex build adding masonry and gallery scripts and some pjaxing to the picture, providing CGI access for the customer)